Accompanied with the requirement for improvement in fuel consumption, automobiles performing idle reduction control have recently drawn attention. In the automobile performing idle reduction control, there is a proposed technique of increasing the state of charge in a battery upon prediction of a traffic jam based on traffic congestion prediction information by an automotive navigation system (Patent Literature 1). An increase in number of engine stops by idle reduction control in a traffic jam increases consumption of the state of charge in the battery. The state of charge in the battery is thus increased in advance, upon prediction of a traffic jam.
The device of Patent Literature 1 is thought to predict a traffic jam as the driving environment causing a vehicle stop, which leads to an engine stop by idle reduction control. Another proposed device predicts running in an urban area as the driving environment causing a vehicle stop (Patent Literature 2). This device predicts running in an urban area, based on the average vehicle speed and the number of vehicle stops in a past given time.